1. Field of the Invention
The present invention relates to a capsule medical apparatus that is introduced into a subject and has a local injection function. The local injection function is for injecting a liquid, e.g., a drug solution, into a desired region inside the subject.
2. Description of the Related Art
In conventional endoscopy technology, capsule medical apparatuses that are introduced into organs of a subject and capture images of the inside of the organs (hereinafter, “in-vivo images”) have been proposed. Such capsule medical apparatuses have imaging and wireless transmission functions therein. The capsule medical apparatus is swallowed by a subject, e.g., a patient, and sequentially captures in-vivo images of the subject while moving through the digestive tracts due to peristalsis or the like. Each time the capsule medical apparatus captures an in-vivo image of the subject, the capsule medical apparatus wirelessly transmits the in-vivo image in sequence to a receiving apparatus, which is located outside the subject. The capsule medical apparatus introduced into the subject is later excreted.
Some capsule medical apparatuses have been proposed that have not only the above functions but also a local injection function for injecting a drug solution into an internal region of a subject (e.g., Japanese Patent Application Laid-Open Nos. 2006-43115 and 2004-41709). The capsule medical apparatus disclosed in Japanese Patent Application Laid-Open Nos. 2006-43115 and 2004-41709 punctures an internal region of a subject with an injection needle and injects a drug solution into the internal region using the injection needle that punctures the internal region. Then, the capsule medical apparatus pulls out the injection needle that punctures the internal region and stores the injection needle in the capsule medical apparatus.
A method for injecting medicines into tissue has been proposed (e.g. Japanese translation No. 2003-530897 of PCT international application). In this method, an injecting apparatus injects a drug solution into tissue and then pulls out an injection needle from the tissue. The injection apparatus cauterizes and hardens a region of the tissue where the injection has been performed, i.e., an injection region, by high frequency cauterization or laser heating to seal the site of the injection in the injection region.